I. Field of the Invention
The present invention relates generally to mechanized systems for covering open top containers with flexible covers for transport and, more particularly, relates to a self-contained vehicle/mounted system for covering vehicle mounted containers that are carried on a variety of vehicles including those permanently mounted on truck vehicles, such as dump trucks, those associated with roll-on/roll-off hoists, and the like. The system is an entirely self-contained unit. The only required connection is to the vehicle electrical system; consequently, the system of the invention can be added or retrofitted without design modifications or changes in any existing vehicle accessory or hydraulic system.
II. Related Art
Open top containers that are carried by trucks, trailers or other similar vehicles and which are used to transport various classes of loose materials are widely used in construction projects, refuse disposal and other endeavors. These include, but are not limited to gravel and dump trucks and roll-on/roll-off container handling trucks, etc. These vehicles are generally required to have the open tops of containers closed or covered when filled dump bodies or other containers are transported on public roads and highways. These dump bodies, containers or boxes (collectively referred to herein as “containers”) are usually rectangular and do resemble large open top boxes from which loaded materials may easily be lost during transport if the load remains uncovered. In addition, the open top enables the entry of rain or snow which can hamper the operation as well.
The tops of these containers are typically closed using a heavy flexible cover material such as a canvas or cloth tarpaulin or “tarp”. The containers are generally quite large with capacities of 10, 20 or even 50 cubic yards. This makes it difficult for a driver to cover or uncover the container by hand, both from the standpoint of manipulating a large cover and the increased risk of injury from climbing up on the truck to manipulate the cover. These difficulties have led to the development of a variety of mechanized systems for covering and uncovering truck-mounted open top containers. These include truck-mounted assemblies that are pneumatically or hydraulically operated to apply and retract flexible covers over the top of open containers carried on vehicles, particularly roll-off containers. These mechanized systems have become known in the art as “tarper” systems.
Examples of such systems include those shown in U.S. Pat. No. 5,829,818 to O'Daniel and in U.S. Pat. No. 7,370,904 to Wood, Jr. et al. The '904 patent is assigned to the same assignee as the present invention.
Prior systems have been required to connect into the existing hydraulic or pneumatic system of a vehicle on which they are installed. This puts an extra burden on the hydraulic or pneumatic system and may require the vehicle to be retrofitted, or otherwise provided, with an additional spool valve, larger oil reservoir, hydraulic pump, etc., or a larger air compressor unit or pressure tank, which may add a great deal of difficulty and cost to the installation.
Thus, while such prior systems have met with a degree of success, there remains a need for a self-contained system with improved mechanical and interlocked control features that provides smooth operation, can be used on a variety of container sizes, and which can be easily added or retrofit to a vehicle needing only an electrical connection to an existing vehicle's electrical system.